1. Field of the Invention
The present invention relates to a drawing device and a method for detecting a shape of a nail in a drawing device.
2. Description of the Related Art
There is generally known a drawing device for drawing a nail design on nails. Such a drawing device is described in JP 2003-534083 W.
With such a device, one can easily enjoy nail design without going to a nail salon.
However, a nail, which is a drawing target of a drawing device for nail print, has a curved shape that becomes lower and steeper toward both ends of a nail in the width direction.
Therefore, when a design image is drawn on a nail without consideration of the curved shape, the design becomes skewed and does not look beautiful.
In order to draw an image without skews on a nail, curve correction needs to be applied to drawing data so that the drawing data deals with the curved shape of the nail. However, the degree of curve of the curved shape of a nail depends on a person. Therefore, it is not possible to determine a constant correction value to make a correction. It is necessary to make a correction according to the degree of curve of the curved shape of each nail of a user.
As a method to obtain curved shape of an object, a light section method is known. In the light section method, a surface of the object is irradiated with line laser light, line formed on the surface of the object by the line laser light is imaged from the oblique direction, and the three-dimensional shape (change of the shape in the height direction and the curved shape) of the object is obtained based on this image.
However, when the object is a nail, laser light irregularly reflects or diffuses on a surface of the nail depending on the surface condition of the nail, and therefore, a line formed on the surface of the nail by the line laser light sometimes blurs. In that case, it is difficult to accurately measure the curved shape of the nail.
Furthermore, when a light section method is used, it becomes necessary to include an irradiation unit for generating line laser light in a drawing device. It leads to increase in size and weight of a device.
In addition, an irradiation unit is a unit not necessary for drawing in a drawing device and has not been included in a drawing device. Therefore, if an irradiation unit is included, increase in cost of a drawing device because of an irradiation unit is inevitable.